US supermajor Chevron has agreed to buy compatriot independent and gas producer PDC Energy for $6.3 billion in a deal that will expand the company’s operations at a pair of shale basins in the country.

The acquisition of PDC provides Chevron with high-quality assets that are expected to deliver higher returns in lower-carbon intensity basins in the US.

The all-stock transaction values PDC at $72 per share and represents a 14% premium on a 10-day average.